EP0724192A1

EP0724192A1 - Photographic film element for recording overlapping digital and pictorial images

Info

Publication number: EP0724192A1
Application number: EP96200080A
Authority: EP
Inventors: Gilbert A. C/O Eastman Kodak Co. Hawkins; Annabel A. c/o Eastman Kodak Co. Muenter; Philip T.S. c/o Eastman Kodak Co. Lau; John D. c/o Eastman Kodak Co. Baloga
Original assignee: Eastman Kodak Co
Current assignee: Eastman Kodak Co
Priority date: 1995-01-25
Filing date: 1996-01-15
Publication date: 1996-07-31
Also published as: JPH08248558A

Abstract

A photographic film element including a substrate (19) and a plurality of layers. One or more of the layers (18) are sensitized to a region in the non-visible portion of the spectrum in addition to layers (12,14,16) sensitized to the visible portion of the spectrum not exposable by the wavelengths exposing the layer or layers sensitive to the non-visible portion of the spectrum, the non-visible sensitized layer or layers being rendered, upon exposure and development, imagewise absorptive of light at wavelengths not substantially absorbed by the dyes produced by the conventionally sensitized layers and substantially less absorptive of light than the conventionally sensitized layers at wavelengths in the visible portion of the spectrum.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

Reference is made to commonly assigned U.S. Serial No. 08/146,347 filed October 29, 1993 entitled "Camera for Recording Digital and Pictorial Images on Photographic Film" by Hawkins et al, the teachings of which are incorporated herein by reference.

Field of the Invention

The present invention relates to a photographic film element for recording digital and pictorial images.

BACKGROUND OF THE INVENTION

Still camera users frequently desire to enhance or document individual pictures with supplementary information, such as text captions or brief audio segments that can be conveniently accessed during viewing of the image. The need for audio segments has been previously recognized, for example, in U.S. Patent No. 3,920,862 which discloses a method of recording sound magnetically in association with still pictures. Nonetheless, such camera systems are not in common use today, owing to the fact that most methods suffer disadvantages due to cumbersome peripheral recording means, specialized data storage means and/or cumbersome playback means, and to the difficulty of synchronizing these functions with image display (see for example, U.S. Patent No. 5,128,700). Optical recording of data such as sound directly on conventional film elements eliminates the need for separate storage means but may reduce the number of conventional images that can be stored or reduce the image size, there being a tradeoff between the amount of digital and pictorial information recorded. Also, a conventional film element is not optimized for recording high density digital data. For example, the grain of a conventional film element is made larger than that desired for digital recording in order to increase photographic speed.

SUMMARY OF THE INVENTION

In view of the foregoing, it is an object of this invention to provide a photographic film element which expands on the amount and type of non-pictorial information which may be captured on the film element by camera users by providing an all-optical means for overlapping the recording of digital and pictorial images.
Another object is to ensure permanent association between an image and the digital information intended to accompany it.
Another object is to provide a film element with the option of recording large amounts of digital data without sacrificing the number, size or quality of conventional images.
Another object is to eliminate the need for a user to choose between digital and pictorial information for film usage.
These objects are achieved in a photographic film element comprising:

(a) a substrate; and
(b) a plurality of layers, including:
- (i) one or more layers sensitized to a region in the non-visible portion of the spectrum; and
- (ii) one or more layers conventionally sensitized to the visible region of the spectrum and not exposable by the non-visible wavelengths exposing the layer or layer(s) sensitized to the non-visible portion of the spectrum;

An advantage of this invention is to enable spatially overlapping records of digital data and conventional pictures.
This invention provides the user of a camera equipped for digital recording with the ability to store digital data on the film element, while providing the full functionality of conventional film to users of cameras not so equipped.
A further advantage is to afford a user the ability to record large amounts of digital data such as sound or text in the same location as a conventional image, thereby ensuring that the image and the digital data remain associated.
The present invention permits the additionally sensitized emulsion layer to be optimized for digital recording.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view of a camera which can use a film element in accordance with the present invention;
FIG. 2 is a rear view of the camera of FIG. 1;
FIG. 3 shows the construction of the linear edge-emitter array used to expose a film element in accordance with the present invention;
FIG. 4 shows a schematic circuit diagram for operating the camera system of FIGS. 1 and 2;
FIG. 5 shows a film element in accordance with this invention along with a cross-section region of the film strip; and
FIGS. 6a and 6b show relative log spectral sensitivities for the layers of film elements exposed in accordance with this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The essential features of the camera in the system depicted in topview FIG. 1 and backview FIG. 2 are image capability in the conventional photographic sense (i.e., ability to allow picture taking on conventional film record sensitive to the visible portion of the spectrum) and electronic, mechanical, and optical capability for acquiring and writing digital information to the film element at wavelengths which do not expose the visible color records of conventional film. (For example, such a wavelength might lie in the infra-red region of the spectrum.) The essential feature of the film element for this system is incorporation of a recording layer which can be exposed by the digital camera writer but which is not exposed by the taking of conventional images at visible wavelengths. The film element must have the capability to produce an imagewise record, upon exposure by the digital writer, which, upon development, absorbs primarily in regions of the spectrum at which the developed visible layers do not absorb or which absorbs a sufficiently small amount in the visible spectrum to enable the visible record to be correctly interpreted when account is taken of any spectral overlap. (For example, such a wavelength might also lie in the infra-red region of the spectrum and might be the same or different from the wavelength of the digital writer in the camera.) The preferred embodiment of the film element and camera system will refer to an infra-red digital exposure means and a film element record sensitive to this means and producing an infra-red optical density.
The camera functions are first discussed. Referring to FIGS. 1 and 2, a microphone 30 is provided for audio recording as well as a receiving means 38 of receiving digital data from at least one external source type, such as an intensity modulated infra-red signal source 32, a radio frequency source 34, or a direct electrical or optical interconnect port 36. The signal from any one of these sources is user selected by selector switch 39 on the camera, is processed digitally by semiconductor processing circuit 40, and is stored in data buffer 42 for subsequent optical encoding on a portion of the film element at the film gate. It will be appreciated by those skilled in the art that the digital electronic capabilities can be implemented in many ways using conventional semiconductor components.
The data source is selected by selector switch 39, the record data button 74 is activated, and the data is immediately recorded on the film element backside in the region of the exposure gate 41 by movable linear emitter array 50 until this region is filled or until the data stream is terminated. A picture taken in association with this data is then permanently linked to the data by virtue of spatial collocation. In a second embodiment, the recorded information is stored in the data buffer 42 for later verification by selection of the verify first mode using verify first button 76 and speaker 82. After verification, obtained by pressing verify buffer button 72, the user then may elect to transfer the contents of the buffer to the film element in the exposure gate region using record buffer button 73.
It will be appreciated that many variants of the data acquisition and record process are possible, for example advancing the film element to a predetermined frame before recording the buffer contents or displaying text in the case that text has been captured. As another example, digital information generated within the camera may also be recorded on the film element in association with particular frames of conventional images, either automatically or by user command.
Recording of the digital information onto the film element in accordance with this invention in the camera of FIGS. 1 and 2 may be accomplished by a variety of means. In the particular embodiment shown in FIG. 3, a high density linear emitter array 50 including edge emitting LED array 53, fabricated by means practiced commonly in the art, using semiconductor materials such as GaAs, AlGaAs, AlGaInAs, or GaInP, contacts the film element back surface and is scanned over the region of the exposure gate 41. Exposure is accomplished by emitters whose intensities are individually controlled by semiconductor driver circuit 51, connected by wire bonds 55 to LED array 53, in response to the information received as selected by selector 39 of FIG. 1. As is known, in the art, alternative ways of modulating the light emitters such as optical switches in the light guides, may also serve the purpose of optical exposure. Array advance means 64 comprised, for example, of a rotating lead screw, moves the linear emitter array 50 over the exposure gate region 41 to cause individual bits of information recorded on the film element 10 to be spaced from one another, thereby producing a two-dimensional array of "dots" recorded as latent images. The logic circuit 44 preferentially controls the rate of array advance during digital recording so that array motion is synchronized to the activation of the emitters in the array by optical encoder track 65 on the camera body and encoder reader 66 on movable linear emitter array 50. This procedure ensures that the digital data is recorded in as small a space as possible. The LED array 53 preferably forms a line array with emitter to emitter spacing preferably in the range 2 to 200 microns and emitting over only a narrow spectral range in the infra-red, for example over a range of from 700 to 740 nm. It is to be recognized by those familiar with film exposure that arrangements other than movable line arrays may be employed to record the digital information, for example two-dimensional LED arrays or laser arrays, or movable mechanical systems such as mirrors or lenses.
Turning now to the preferred embodiment of the film element, with reference to FIG. 5, region 20 of the film element 10, typically exposed in accordance with this invention, is shown in cross-section to contain conventional photographic color records ( layers 12, 14 and 16) sensitive to red, blue and green light coated sequentially on a conventional film base 19. In addition, a record layer (layer 18) is shown coated on the opposite side of film base 19. An image record, shown in cross-section 21, has been established in each of the three visible color sensitive layers 12, 14 and 16 and in the infra-red sensitive record layer 18. The shading in cross-section 21 indicates the presence of a latent image. The dots in region 20 of film element 10 depict only the digital image record of infra-red sensitive record layer 18, the image records of layers 12, 14 and 16 not being shown in region 20 for clarity.
In the visible spectrum, absorption in the layers 12, 14, and 16 superimposes to provide full spectral image content in the conventional photographic sense. There is no appreciable interference from infra-red record 18 in viewing or printing this image because, in accordance with this invention, layer 18 does not absorb appreciably in the visible region of the spectrum, in either the exposed (shaded) or the unexposed regions. As shown in FIG. 5, layer 18 has been used in accordance with this invention to store digital data on the film element 10 in response to a particular information source chosen by the user. In the case drawn, the film space taken by this information is in the same film region 20, cross-section 21, that is occupied by the conventional pictures. Because records 12, 14, and 16 do not absorb strongly in the infra-red, either in the exposed or the unexposed regions, as is well known in the state of the art of conventional photographic science, whereas layer 18, in accordance with this invention, absorbs in the infra-red in regions where it was exposed, the digital data record stored in layer 18, depicted by dots in region 20, may be retrieved by measuring the infra-red transmission through the film element, as may be done, for example, by scanning the film element for optical density in the infra-red portion of the spectrum. Film element 10 thereby permits optimal use of mixed pictorial/non-pictorial recording, since the digital and pictorial information may be spatially overlapped. This format also provides higher potential storage densities of digital information than would conventional film color records, because layer 18 can be optimized for digital recording, for example in speed and grain, independent of the need to capture conventional images.
The film element claimed in accordance with this invention is accomplished by the addition of layer 18 to an otherwise conventional photographic film element, either on the film element substrate back surface, as described in the detailed embodiment herein, or as an additional layer on the front surface of the substrate, preferably the layer nearest the substrate, as taught in commonly-assigned U.S. Patent No. 5,108,882 issued April 28, 1992 to Patton et al which gives recipes for the incorporation of multilayer coatings one or more of which are infra-red sensitized.
The infra-red sensitive layer can be comprised of AgCl, AgBr, AgBrI or other mixed halide emulsions which may be cubic, octahedral, or tabular in their morphology. Emulsions of cubic morphology are particularly useful because of their resistance to dye desensitization by the infra-red dyes. These emulsions can be chemically sensitized with typical treatments of sulfur and/or gold containing compounds. The sensitizing dyes used are typically dicarbo, tricarbo or tetracarbo cyanine dyes which may contain a variety of heterocyclic ring structures and various other substituents. Also, various addenda, especially substituted bis-azine compounds, are useful in combination with the dyes to improve their sensitizing ability. Other addenda, such as tetraazaindenes or phenylmercaptotetrazoles (See James, The Theory of The Photographic Process, 4th Edition, MacMillen, New York, 1977, Chapter 13) are useful to improve the keeping stability of the dyed emulsions. The infra-red couplers useful in the present invention are typically 1-naphthols containing a variety of carboamido substituents at the 2-position of the naphtholic ring.
A preferred embodiment of this layer is now described beginning with a preferred class of infra-red sensitive dyes. Formula I shows a preferred class of infra-red sensitizers having the formula:

wherein:
Z₁ and Z₂ each independently represents the atoms necessary to complete a substituted or unsubstituted 5- or 6- membered heterocyclic nucleus
R₁ and R₂ each independently represents substituted or unsubstituted alkyl
R₃ and R₄ each independently represents hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted aryl
n is 0 or 1
X represents a counterion
Examples of dyes according to Formula I are set forth below in Tables I and II.
An additional preferred class of infra-red sensitizers is given in Formula II:

wherein
Z₃ and Z₄ each independently represents the atoms necessary to complete a substituted or unsubstituted 5- or 6- membered heterocyclic nucleus.
R₅ and R₆ each independently represents substituted or unsubstituted alkyl or substituted or unsubstituted aryl, and
R₇, R₈, R₉, and R₁₀ each independently represents hydrogen, substituted or unsubstituted alkyl substituted or unsubstituted aryl,
X represents a counterion.
Examples of dyes according to Formula II are set forth below in Table III, IV and V, as taught in commonly assigned U.S. Patent No. 5,108,882, the disclosure of which is incorporated herein by reference. These dyes give spectral sensitivity distributions exhibiting narrow bands with peak sensitivities in the infra-red and correspondingly low sensitivity in the visible region of the spectrum, as desired for the infra-red sensitive layer of this invention.
Tricarbocyanine dyes and their methods of synthesis are well known in the art. Synthetic techniques for known tricarbocyanine dyes, such as set forth by Hamer, Cyanine Dyes and Related Compounds, John Wiley & Sons, 1964, apply equally as well to the dyes of Formula (II). Synthesis of the dyes of Formula (II) is also described in U.S. Patent No. 3,582,344 and A. I. Tolmachev et al, Dokl. Akad. Nauk SSSR, 177, 869-872 (1967), the disclosures of which are incorporated herein by reference.
While Formulae I and II are examples of preferred embodiments, essentially any known spectral sensitizing dye sensitizing substantially in the infra-red portion of the spectrum is useful as a spectral sensitizer for the infra-red sensitive layer of this invention, including those described in one or more of the following references: U.S. Patent Nos. 2,095,854; 2,095,856; 2,734,900; 2,955,939; 3,482,978; 3,552,974; 3,573,921; 4,975,362; 5,061,618; 5,037,734; Hamer, Cyanine Dyes and Related Compounds, John Wiley & Sons, 1964, as well as in Mees, The Theory of the Photographic Process, 3rd Ed. (MacMillan, 1966) pp 198-201.
The infra-red sensitizing dyes disclosed above are added to photographic silver halide emulsions to form the infra-red sensitive layer of this invention. These silver halide emulsions can contain grains of any of the known silver halides, such as silver bromide, silver chloride, silver bromoiodide, and the like, or mixtures thereof, as described in Research Disclosure, Item 17632, Dec. 1978 (hereinafter referred to as Research Disclosure I), Section I. The silver halide grains may be of any known type, such as spherical, cubic, or tabular grains, as described in Research Disclosure I, Section I, or Research Disclosure, Item 22534, Jan. 1983. Because of their ability to record the high resolution, low granularity images desired for this invention, fine-grained silver halide emulsions, with equivalent spherical diameters of 0.5 µm or less, are especially preferred.
As is well known in the art, all of the emulsion types described in the preceding paragraph are rendered developable by exposure to radiation at wavelengths shorter than visible light, such as ultraviolet radiation at 365 nm. As a result, in an alternate embodiment, the emulsions are used to form a layer which responds to non-visible light in the short wavelength region of the spectrum. This layer is separated from the layers sensitized to the visible portion of the spectrum by coating it on the backside of the support. The support is highly absorptive of non-visible light in the short wavelength region of the spectrum and for exposures made from the backside, acts as a filter to prevent this non-visible light from exposing the layers sensitized to the visible portion of the spectrum.
The silver halide emulsions generally include a hydrophilic vehicle for coating the emulsion as a layer of a photographic element. Useful vehicles include both naturally-occurring substances such as proteins, protein derivatives, cellulose derivatives (e.g., cellulose esters), gelatin (e.g., alkali-treated gelatin such as cattle bone or hide gelatin, or acid-treated gelatin such as pigskin gelatin), gelatin derivatives (e.g., acetylated gelatin, phthalated gelatin, and the like), and others described in Research Disclosure I. Also useful as vehicles or vehicle extends are hydrophilic water-permeable colloids. These include synthetic polymeric peptizers, carriers, and/or binders such as poly(vinyl alcohol), poly(vinyl lactams), acrylamide polymers, polyvinyl acetals, polymers of alkyl and sulfoalkyl acrylates and methacrylates, hydrolyzed polyvinyl acetates, polyamides, polyvinyl pyridine, methacrylamide copolymers, and the like as described in Research Disclosure I. The vehicle can be present in the emulsion in any amount known to be useful in photographic emulsions.
The emulsion can also include any of the addenda known to be useful in photographic emulsions. These include chemical sensitizers, such as active gelatin, sulfur, selenium, tellurium, gold, platinum, paladium, iridium, osmium, rhenium, phosphorous, or combinations thereof. Chemical sensitization is generally carried out at pAg levels of from 5 to 10, pH levels of from 5 to 8, and temperatures of from 30° to 80°C., as illustrated in Research Disclosure, June 1975, Item 13452 and U.S. Patent No. 3,772,031.
Other addenda include brighteners, antifoggants, stabilizers, filter dyes, light absorbing or reflecting pigments, vehicle hardeners such as gelatin hardners, coating aids, dye-forming couplers, and development modifiers such as development inhibitor releasing couplers, timed development inhibitor releasing couplers, and bleach accelerators. These addenda and methods of their inclusion in emulsion and other photographic layers are well-known in the art and are disclosed in Research Disclosure I and the references cited therein. As disclosed in commonly assigned U.S. Patent No. 5,108,882, a preferred embodiment of the infra-red sensitized emulsion layer contains one or more bis-azine compounds as supersensitizing addenda.
The emulsion layer containing silver halide sensitized with the dye of the invention can be coated simultaneously or sequentially with other emulsion layers, subbing layers, filter dye layers, or interlayers or overcoat layers, all of which may contain various addenda known to be included in photographic elements. These include antifoggants, oxidized developer scavengers, DIR couplers, antistatic agents, optical brighteners, light-absorbing or light-scattering pigments, and the like.
Color dye-forming couplers and the various addenda associated therewith are well-known in the art and are described, for example, in Research Disclosure I, Section VII, and the references cited therein. In the practice of this invention, it is required that the dye produced by the coupler in the layer sensitized to the non-visible portion of the spectrum absorb in regions of the spectrum not appreciably overlapping with the regions of absorption of the other color records, in order that the developed record of digital data not interfere with the viewing or printing of the color records providing the pictorial content of the film frame even when the digital and pictorial records are overlapping. In the preferred embodiments, this coupler forms dye whose absorption lies in the infra-red and whose development chemistry for the digital latent image is compatible with standard development procedures for photographic film element as is well known and practiced in the art.
Preferred infra-red dye forming image couplers useful in the present invention are shown in the Table VI below:
It is to be recognized that other classes of infra-red couplers may also serve the purposes of this invention and that the exact spectral absorption characteristics need not be critical as to spectrum or intensity of light transmitted through the developed layer either in regions of exposure or in regions where there is no exposure, because the data represented by the developed infra-red layer is digital in nature and is not subject to the need for exacting color balance as are dyes in the visible color record of conventional film elements.
The layers of the photographic element can be coated onto a support using techniques well-known in the art. These techniques include immersion or dip coating, roller coating, reverse roll coating, air knife coating, doctor blade coating, stretch-flow coating, and curtain coating, to name a few. The coated layers of the element may be chill-set or dried, or both. Drying may be accelerated by known techniques such as conduction, convection, radiation heating, or a combination thereof.

EXAMPLES

The practice of this invention is described below with reference to specific illustrative examples. However, the invention is not to be construed as being limited by these specific examples.

Example 1: Infra Red Light Sensitive Photographic Material

On a cellulose triacetate film support provided with a subbing layer plus an intermediate layer containing 4.89 g/m² gel, two layers having the composition set forth below were coated to prepare a color photographic infra-red light sensitive material which was designated sample 101. In the composition of the layers, the coating amounts are shown as g/m². The chemical formula of dye I-1 is given in Table 1 and the chemical formulae of dyes SD-2 and SD-3, bis-azine compound T-1, couplers IR-1, IR-2, C-1, M-1 and Yel-1, solvents S-1 and S-2, and hardener H-1 are given in Table VII.

First Layer: Infra-red Light Sensitive Layer

The light sensitive element in this layer is a cubic AgBr emulsion, 0.25 µm in edge length, sulfur and gold sensitized, and spectrally sensitized to infra-red light with a 4.2 x 10^-5 mole/mole Ag of dye I-1. The emulsion also contained as addenda 7.8 x 10^-4-mole/mole Ag of the bis-azine supersensitizer T-1 and a substituted tetraazaindene antifoggant.

Silver Bromide Emulsion 0.81 (as silver)

Infra-red Coupler IR-1 0.86

dispersed in solvent S-1 0.86

Gelatin 2.37

Second Layer: Overcoat Layer

Gelatin	0.97
Matte Beads	0.02
Hardener H-1	0.12

Sample 102 was prepared in the same manner as described above for sample 101 except for the change in coupler in the first layer listed in Table VIII. All couplers were coated at 0.86 g/m².

Example 2: Green Light Sensitive Photographic Material

On a cellulose triacetate film support with a subbing layer plus an intermediate layer containing 4.89 g/m² gel two layers having the composition set forth below were coated. The green light sensitive photographic material was designated sample 201. In the composition of the layers, the coating amounts are shown as g/m^2.

First Layer: Green Light Sensitive Layer

The light sensitive element in this layer is a tabular AgBrl emulsion with 4.5% bulk iodide, 1.05 µm in diameter and 0.12 µm thick. The emulsion was sulfur and gold sensitized and spectrally sensitized to green light with 6 x 10^-4 mole/mole Ag of dye SD-2 and 2 x 10^-4 mole/mole Ag of dye SD-3.

Silver Iodobromide Emulsion 0.81 (as silver)

Magenta Coupler M-1 0.86

dispersed in solvent S-2 0.43

Gelatin 2.37

Second Layer: Overcoat Layer

Gelatin	0.97
Matte Beads	0.02
Hardener H-1	0.12

Samples 202 and 203 were prepared in the same manner as described above for sample 201 except for the change in coupler in the first layer, listed in Table VIII All couplers were coated at 0.86 g/m².

Solvent S-1: tri-(2-ethylhexyl)phosphate
Solvent S-2: Phosphoric acid, tris(methylphenyl) ester
Hardener H-1: bis(vinylsulfonyl) methane
Each of the samples thus prepared were cut into 35 mm width strips. The samples were given a 1 second stepped exposure to a simulated daylight light source through a Kodak Wratten 89B filter. This filter blocks blue, green, and red light but passes infra-red light. The simulated daylight light source conforms to American National Standard for Simulated Daylight ANSI PH2.29-1987 (R-1976). The spectral characteristics of Kodak Wratten 89B filter are described in "Kodak Filters for Scientific and Technical Uses, Publication B-3.
After exposure, the samples were processed using Kodak C-41 processing solutions to produce a negative image. The developer processing time was 3 minutes and 15 seconds. The samples were also processed using Kodak E-6 processing solutions to produce a reversal image. However, the first developer processing time was reduced from the standard 6 minutes to 4 minutes to compensate for the rapid development rate of a single layer light sensitive photographic material. Kodak process C-41 and E-6 are described in the British Journal of Photography Annual 1988.
For all samples, the Status A red, green, and blue densities were measured for all of the steps. A spectrophotometric analysis was also performed on all steps. Methods used to obtain Status A densities are described in James, editor, The Theory of the Photographic Process, 4th Edition, MacMillen, New York, 1977, Chapter 18.
After 1 second exposure through a Kodak Wratten 89B filter, infra-red sensitized samples 101 through 102 produced a photographic sensitometric scale in both C-41 and E-6 processes. However, green sensitized samples 201 through 203 produced no sensitometric scale since these samples contained no infra-red sensitive emulsion.
When samples 201 through 203 were given a 1/25 second stepped exposure to a simulated daylight light source through Kodak Wratten 2C plus Wratten 12 filters (described in Kodak Publication B-3), they produced a photographic sensitometric scale in both C-41 and E-6 processes. These filters remove blue light but pass red and green light and therefore caused exposure to the green sensitized emulsion.

Selected data from the spectrophotometric analysis of the E-6 processed film is shown in Table VIII. Similar data were obtained from the C-41 processed film leading to the data in Table IX.

TABLE VIII

E-6 Process Data
Sample	Coupler	λmax	Density Ratio
			750nm	700nm	650nm	550nm	450nm
101	IR-1	810nm	.71	.57	.33	.06	.08
102	IR-2	830nm	.73	.63	.37	.06	.08
201	M-1	550nm	.03	.04	.07	1.00	.17
202	C-1	660nm	.33	.81	.99	.21	.08
203	YEL-1	450nm	.03	.03	.03	.05	1.00

TABLE IX

C-41 Process Data
Sample	Coupler	λmax	Density Ratio
			750nm	700nm	650nm	550nm	450nm
101	IR-1	700nm	.74	1.00	.82	.07	.11
102	IR-2	720nm	.87	.96	.56	.08	.08
202	C-1	670nm	.43	.90	.96	.14	.08

In Tables VIII and IX, λmax refers to the wavelength (nanometer units) at which maximum spectral density occurs. Density ratio is defined as the spectral density at the wavelength indicated in the table divided by the spectral density at λmax.
In this invention, an infra-red coupler is defined as one that forms dye whose spectral density ratio at any wavelength greater than or equal to 700 nm exceeds its density ratio at all wavelengths below 700 nm. Such couplers can be electronically detected by infra-red sensors. Such couplers produce infra-red absorbing dyes whose unwanted absorption at visible wavelengths is lower than their absorption at infra-red wavelengths. Information from such couplers can easily be distinguished and subtracted from cyan, magenta, and yellow visible imaging couplers by electronic and/or digital means, as is well known in the art. The interference information from these couplers at visible wavelengths can be more accurately subtracted out of the signal from visible dye forming couplers as the infra-red dye's contribution at visible wavelengths becomes smaller. An ideal infra-red coupler would have substantially no absorption at visible wavelengths. In this case, no electronic correction for unwanted absorption would be needed.
The density ratios listed in Table VIII and Table IX show that infra-red couplers IR-1 and IR-2 satisfy the requirements of an infra-red coupler in this invention in both C-41 and E-6 processes as compared to couplers C-1, M-1, and YEL-1.
To determine the spectral sensitivity distributions of samples 101, 102, and 201, the samples were exposed on a wedge spectrographic instrument which covers the wavelength range from 440 nm to 840 nm. The instrument contains a tungsten light source and a step tablet ranging in density from 0 to 3 density units in 0.3 density steps. Samples 101 and 102 were exposed for 2 seconds while sample 201 was exposed for 1/25 second. After exposure and processing in Kodak C-41 processing solutions, speed was read at 10 nm intervals at a density of 0.3 above fog. Correction for the instrument's variation in spectral irradiance with wavelength was done via computer. Plots of log relative spectral sensitivity of samples 101, 102 and 201 are shown as a function of wavelength in FIGS. 6a and 6b. An approximate correction for the exposure time difference is also included in these plots. The plots illustrate the photographic sensitivity of the infra-red sensitized emulsion at wavelengths longer than 700 nm and the insensitivity of the emulsion at visible wavelengths below 700 nm. In the same way, the green sensitized emulsion in sample 201 shows its photographic sensitivity toward visible light and its lack of sensitivity toward infra-red light. These data illustrate that samples 101 and 102 can be selectively exposed apart from sample 201 by using infra-red light at wavelengths above 700 nm. Likewise, sample 201 can be selectively exposed apart from sample 101 or 102 by using green light.
The infra-red sensitized emulsion also has some intrinsic sensitivity to blue light at wavelengths below 480 nm. This sensitivity can be removed in a photographic material by means well known in the art such as Carey Lea Silver coated in an interlayer positioned anywhere between the light source and the infra-red sensitized layer. Alternatively, a blue light imaging layer can be positioned between the light source and the infra-red layer thereby absorbing blue light and preventing blue light exposure to the infra-red layer.
A further means of preventing blue exposure of the infra-red sensitive layer is to choose an infra-red sensitive emulsion which has an overall low sensitivity to light exposure. In this case, the amount of blue light needed to expose this infra-red sensitive layer can be made to be much larger than the light needed to expose the blue light imaging layers used to form the conventional pictorial image. The blue light imaging layers can thus be exposed without exposing the infra-red sensitive layer. Exposure of the infra-red sensitive emulsion by the infra-red exposure means will still be possible, since the amount of infra-red light employed by this exposure means can be adjusted to compensate for the low overall sensitivity of the infra-red emulsion. Such low sensitivity emulsions can be produced by techniques well known in the art, including the use of emulsions with equivalent spherical diameters below 0.3 µm, incorporation of desensitizing metal ion dopants, adjustment of chemical sensitization procedures, and addition of desensitizing addenda.
These examples demonstrate the practice of this invention since multilayer photographic materials can be constructed by adding a layer containing an infra-red sensitized emulsion with an infra-red image coupler to a conventional multilayer photographic material having one or more layers with conventional image couplers and emulsions sensitized to visible light. By this arrangement, information can be written separately to the infra-red layer using infra-red light. After processing the photographic material using standard process solutions, the information recorded by the infra-red imaging coupler can be electronically separated from the non-infra-red image by scanning and processing algorithms well known in the art. For example, methods to subtract unwanted spectral absorptions from dye sets are described in Hunt, The Reproduction of Color, 4th Edition, Fountain Press, England, Chapter 14.
In the practice of this invention, the spectral absorption of the infra-red coupler should differ from that of all visible image couplers used in the photographic material so that the dye information recorded by the infra-red layer can be distinguished from the dye information recorded by all visible imaging layers in the photographic material.
In an ideal case where the infra-red exposure to the infra-red layer is constant and binary, as in recording dots for digital information, the unwanted absorption of the infra-red dye can be pre-determined as a function of visible wavelength, stored in a computer, and computationally subtracted from an image signal at visible wavelengths.
If the infra-red exposure is not constant, techniques well known in the art that draw upon the pre-determined spectral absorptions of all dyes present in the film may be used to subtract the contribution of the unwanted infra-red dye at visible wavelengths from the image signal at visible wavelengths. (Hunt, Chapter 14).
If it is desirable to produce a visible image in the photographic material that is suitable for direct viewing, ideally an infra-red coupler would be chosen that produces a dye having substantially no absorption at visible wavelengths.
Since most infra-red couplers will produce dye having some unwanted absorption in the visible region which compromises the direct viewing properties of the photographic material, the infra-red dye may be removed after its information is scanned and recorded. For example, if the infra-red layer was coated on the opposite side of the support from the visible imaging layers, its image can be removed by bleaching the infra-red dye for 30 to 60 seconds using a permanganate-sulfuric acid retouching bleach described in Kodak Publication E68 applied selectively to the infra-red layer only. Other total bleaches known in the art may also be used.
Other methods can be used to completely remove the infra-red layer from the photographic material. For example, a gelatin based infra-red layer may be removed by enzymolysis using a Takamine solution. It may also be removed using a 5% hypochlorite solution. Alternatively, if the infra-red layer were coated in an organic binder, suitable organic solvents may be used to dissolve the binder and wash the layer off the photographic material. Alternatively suitable organic solvents may be used to soak the dye out of the infra-red layer while leaving the layer otherwise intact.
The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.

PARTS LIST

10: film strip
12: top color sensitive layer
14: middle color sensitive layer
16: bottom color sensitive layer
18: record layer
19: film base
20: film region
21: cross-section
30: microphone
32: infra-red signal source receiver
34: radio frequency source receiver
36: direct interconnect port
38: receiving means
39: selector switch
40: semiconductor processing circuit
41: exposure gate
42: data buffer
44: logic circuit
50: linear emitter array
51: driver circuit
53: LED array
55: wirebonds
64: array advance means
65: encoder track
66: encoder reader
72: verify buffer button
73: record buffer button
74: record data button
76: verify first button
82: speaker

Claims

A photographic film element comprising:
(a) a substrate; and

(b) a plurality of layers, including:
(i) one or more layers sensitized to a region in the non-visible portion of the spectrum; and

(ii) one or more layers conventionally sensitized to the visible region of the spectrum and not exposable by the non-visible wavelengths exposing the layer or layer(s) sensitized to the non-visible portion of the spectrum;

the layer or layers sensitive to the non-visible portion of the spectrum being rendered, upon exposure and development, imagewise absorptive of light at wavelengths not substantially absorbed by the dyes produced by the conventionally sensitized layers and substantially less absorptive of visible light than the exposed and developed layers sensitized to wavelengths in the visible region of the spectrum.
The invention of claim 1 wherein the one or more layers sensitized to the non-visible portion of the spectrum is disposed on the film backside.
The invention of claim 1 wherein the one or more layers sensitized to the non-visible portion of the spectrum is disposed on the film backside and is removable from the backside.
The invention of claim 1 wherein the film layer(s) exposable by the non-visible portion of the spectrum includes a color record imagewise exposable at infra-red wavelengths.
The invention of claim 1 wherein the film layer(s) exposable by the non-visible portion of the spectrum produces, upon development, dyes absorptive in the infra-red portion of the spectrum where exposed yet which is substantially transmissive to light in the visible region of the spectrum.
The invention of claim 1 wherein the film layer(s) exposable by the non-visible portion of the spectrum include records imagewise exposable at infra-red wavelengths and which, upon exposure and development, imagewise absorb light also at infra-red wavelengths.
The invention of claim 1 wherein the film layer(s) exposable by the non-visible portion of the spectrum produce, upon exposure and development, absorption of light in the visible portion of the spectrum which can be subtracted from the absorption of light by the entire film element in the visible portion of the spectrum in a manner such that the absorption of visible light by only those layers exposable by visible light is substantially approximated.